So go to Settings–> About phone, then tap 'Build number' seven times quickly to enable Developer Options, then open the menu from Settings –> System –> Advanced (or the bottom of Settings) and enable 'USB debugging.' On the secondary phone that you want to send commands to, you'll need to enable the 'USB debugging' toggle in Developer Options so the phone will accept commands. Tap 'Install' and grant Magisk Manager access to your media if prompted, then it will be installed. Here, tap the search icon and enter 'adb' into the field, then tap the download button next to the ADB & Fastboot for Android NDK module. On your already-rooted phone, head into the Magisk Manager app and tap the puzzle piece icon on the menu bar at the bottom of the screen. Step 1: Install ADB & Fastboot for Android

More Info: How to Install ADB & Fastboot on Mac, Linux & Windows.

You can always check the link below for the regular ADB and Fastboot computer instructions instead. If you don't currently have a spare phone with root access or don't know how to do that, this might not be for you. This guide is mainly for someone who already has a rooted Android device.

USB Type-C data cable or OTG adapter for connecting the two phones.

rooted Android device with USB OTG support.

Don't Miss: How to Send ADB Commands to Your Own Phone Without a PC.

This means you can also unlock the bootloader on other phones, install TWRP directly, and even root them via Magisk - no computer needed! You can then connect it to another phone with a USB Type-C cable and send commands to the child device. The ADB and Fastboot Magisk module, by osm0sis and Surge1223, will turn your phone into an ADB terminal using root access. But with the right setup, you can now send commands to a phone using another phone. ADB and Fastboot are powerful tools that have always required a computer.

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